<style type="text/css">
#buscador_principal {
	margin-left:auto;
	margin-right:auto;
	font-size:18px;
}
</style>
<div id="buscador_principal">
<form method="post" action="{self}">
<input name="accion" value="buscar" type="hidden">
<input type="text" size="60" maxlength="100" name="q" value="{q}">
<input type="submit" id="btn_buscar" class="fg-button ui-state-default ui-corner-all" value="Buscar">
</form>
</div>